The first way is free and can be found during N7:Cerberus Fighterbase mission. Search the control panel near the first objective to find this easily missed item.

The second option, which appears only after you finish the mission and if you fail to pickup the item, is to purchase them from a specific place on the Citadel. Head to the Spectre requisitions terminal inside the Spectre office of the Citadel and note that heating stabilizers are conveniently for sale here. For 1000 credits, this item will sufficiently suit the salarian's needs.